Syringe

ABSTRACT

A syringe includes a holding portion that accommodates an injection objective substance, a driving portion that applies injection energy, and a nozzle portion that includes a passage for injection, with these portions being loaded into a housing independently, whereby a state where the injection objective substance can be injected is established. The syringe includes a regulating means for regulating a loading position of the holding portion and the driving portion within the housing so that a loading state, where the holding portion and the driving portion are always loaded in the same order into the housing, is established for injection of the injection objective substance. Due to this, it is possible to facilitate injection of injection liquid ideal for various purposes and to improve user&#39;s convenience.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/400,534, filed Nov. 11, 2014, which is the U.S. National Phase under35 U.S.C. §371 of International Application No. PCT/JP2013/063171 filedon May 10, 2013 which claims the benefit of Japanese Patent ApplicationNo. 2012-109863 filed on May 11, 2012, the entire contents of which areincorporated by reference herein.

The present invention relates to a syringe that injects an injectionobjective substance into an injection target area of a living body.

BACKGROUND ART

Needleless syringes perform injection without using an injection needle.They generally have a configuration in which pressure is applied to aninjection liquid, which includes a medicine or the like, with the aid ofa propellant, a pressurized gas, a spring, or the like. The pressureapplied to the injection liquid is adjusted so as to deliver theinjection liquid to a desired area inside a living body. Patent Document1 discloses a configuration in which an injection liquid and a gasgenerating agent for applying pressure form one unit. The configurationalso includes a lid that covers the unit. The unit is inserted into asyringe body before using the syringe. The inserted unit will be readyfor injection when the lid is blocked. A new unit is loaded after theinitial unit has been used. Thereafter, a subsequent injection procedureis performed.

Patent Document 2 discloses a configuration that includes an injectionliquid holding portion and a pressurizing portion. The injection liquidholding portion retains an injection liquid. The pressurizing portionapplies pressure to the injection liquid. The injection liquid holdingportion is separated from the pressurizing portion. In thisconfiguration, the injection liquid holding portion and a driving sourceof the pressurizing portion are replaced after the injection liquid isinjected. Thereafter, a subsequent injection procedure is performed.

Patent Document 1: U.S. Pat. No. 6,258,063

Patent Document 2: Japanese Translation of PCT Application No.2003-535654

Patent Document 3: US Patent Application Publication No. 2003/0114789

DISCLOSURE OF THE INVENTION

Regardless of presence of an injection needle, when an injection liquidis injected into an injection target area, injection conditions changedepending on the subject person and the purpose of injection. Theinjection conditions include the kind and amount of injection liquid,the magnitude of load applied to the injection liquid in order todeliver the injection liquid to the injection target area. Thus, inorder to perform injection under intended conditions, the syringe needsto have a configuration corresponding to the conditions. However, eventhe syringe having the above corresponding configuration may not besufficiently convenient for a user to use it.

The present invention has been made in view of the problem. An object ofthe present invention is to provide a syringe that can facilitate liquidinjection ideal for various purposes and improve a user's convenience.

In order to solve the problem, a syringe of the present inventionincludes a configuration that can regulate an order in which constituentportions of the syringe are loaded into a syringe housing. With thisconfiguration, even if there is an error in the order of loading theconstituent portions into the syringe housing, the user can immediatelyrecognize the loading error. Thus, it is possible to improve theconvenience of a user who uses a syringe.

Specifically, the present invention provides a syringe that injects aninjection objective substance into an injection target area of a livingbody. The syringe includes a housing, a holding portion, a drivingportion and a nozzle portion. The holding portion accommodates theinjection objective substance. The driving portion applies injectionenergy toward the injection objective substance accommodated in theholding portion, from the holding portion. The nozzle portion includes apassage, through which the injection objective substance injected fromthe holding portion flows, and injects the injection objective substancefrom an open end of the passage to the injection target area. Theholding portion, the driving portion, and the nozzle portion are loadedinto the housing independently, such that the injection objectivesubstance is ready for injection. The syringe further includesregulating means for regulating a loading position of the holdingportion and the driving portion within the housing so that the holdingand driving portions are always loaded in the same order into thehousing for substance injection.

In the syringe according to the present invention, the holding portion,the driving portion and the nozzle portion are certain constituentportions of the syringe. The holding portion accommodates the injectionobjective substance. The driving portion applies an injection energy tothe injection objective substance. The nozzle portion has a passage forinjecting the injection objective substance. Substance injection isprepared when the three constituent portions are loaded into the housingin an independent manner. In the syringe, the driving portion appliesinjection energy to the injection objective substance accommodated inthe holding portion. The injection objective substance flows through thepassage of the nozzle portion and is injected to the injection targetarea from the open end of the passage. The injection objective substancecontains a component which is expected to exhibit effects inside theinjection target area. As described above, the injection energy appliedby the driving portion is the driving source that performs the injectionof the injection objective substance. Therefore, an accommodation stateof the injection objective substance in the syringe and a specificphysical form of the injection objective substance (a liquid or gelform, powder, granular solid) are not particularly limited, as long asthe injection objective substance can be injected by the drivingportion.

For example, the injection objective substance is a liquid and may besolid in a gel form, provided that the solid has such fluidity forinjection. Further, the injection objective substance may be in a powderstate. The injection objective substance may contain a component to bedelivered to the injection target area of the living body. The componentmay exist in a state of being dissolved in the injection objectivesubstance or may exist in a simply mixed state without being dissolved.Examples of the component to be delivered include vaccines for enhancingantibody, proteins for cosmetic treatments, and cultured cells forregenerating hair. These components are contained in fluid in a liquidor gel form so that the components can be injected, whereby theinjection objective substance is formed.

Further, various energy sources can be used for allowing the drivingportion to apply the injection energy to the injection objectivesubstance as long as the injection objective substance can be injected.Examples of the injection energy source include an energy source whichuses the pressure of gas generated with combustion of ignition chargeand an energy source which uses an electric actuator (for example, amotor, a piezoelectric device, and the like) for applying pressure.

When the injection objective substance is supplied to a living bodyusing the syringe according to the present invention, the kind of theinjection objective substance used varies since the effects changedepending on a size, an age, and a gender of the living body. Moreover,the thickness of the injection target area differs depending on thelayer of biological tissues such as the epidermis layer, theintracutaneous layer, the subcutaneous layer, and the muscle layer. Theload applied to the injection objective substance needs to be adjustedso that the injection objective substance reaches the respective depths.Thus, the holding portion, the driving portion, and the nozzle portionare configured to be independent from each other and are loaded into thehousing in an independent manner.

A plurality of types of holding portions for accommodating a pluralityof kinds and amounts of injection objective substances are prepared.Furthermore, a plurality of types of driving portions for applying aplurality of types of energy sources that supply the injection energy tothe injection objective substance are prepared. These constituentportions are combined appropriately for the injection purposes and areassembled into the housing of the syringe. Further, a plurality of typesof nozzle portions having various shapes may be prepared and included inthe combination. This makes it easy to adjust a mode of injection of theinjection objective substance. For example, the injection mode includesdiameters of the passages for the injection objective substance injectedinto a plurality of positions of the injection target area. By combiningthe respective constituent portions of the syringe for appropriateinjection purposes, the usability and convenience of the syringeaccording to the present invention are improved.

The plurality of types of driving portions may include differentamounts, shapes, dimensions, and the like. Here, the energy source is anignition charge or a gas generating agent and may be driving portions inwhich different amounts of gas are filled when the energy source is apressurized gas. Further, the driving portions may have different springconstants when the energy source is a spring. Moreover, the plurality oftypes of holding portions may include different kinds, amounts, and thelike in which injection objective substances are filled.

It may be possible to facilitate injection of the injection objectivesubstance suitable for various injection purposes by appropriatelycombining the holding portion, the driving portion, and the nozzleportion and loading the same into the housing. However, the syringe maynot function properly if there is an error in the order of loading therespective constituent portions in relation to the housing. In such acase, it may be desirable that users can recognize the error in theloading order immediately, which can enhance the convenience of thesyringe. Moreover, by allowing users to load the respective constituentportions in a proper order, the syringe can allow for stable andreliable injection.

The syringe according to the present invention includes the regulatingmeans that regulates the loading position of at least the holdingportion and the driving portion in relation to the housing. When theholding portion and the driving portion are loaded into the housing, therelative loading position of the holding portion and the driving portionis determined at a predetermined position based on a configuration. Inthe configuration, the injection energy supplied from the drivingportion is applied to the injection objective substance accommodated inthe holding portion, so as to inject the injection objective substance.Thus, when the holding portion and the like are loaded at a positiondifferent from the predetermined position, the syringe cannot properlyinject the injection objective substance. However, in the syringeaccording to the present invention, the loading position of the holdingportion and the like to the housing is regulated uniquely by theregulating means. This can avoid a state where the holding portion andthe driving portion are loaded in the housing at a position other thanthe regulated loading position. If there is an error in the order ofloading the holding portion and the like, the user can recognize theloading error immediately. Thus, it is possible to realize variousinjection modes without degrading the user's convenience.

The holding portion may be disposed after used once and a new holdingportion may be assembled to perform injection. Similarly, the drivingportion and the nozzle portion may be disposed after used once and newdriving and nozzle portions may be used. Alternatively, the drivingportion and the nozzle portion may be used repeatedly if they allow forrepeated uses. Since the housing of a syringe basically can be usedrepeatedly, it is not necessary to prepare a plurality of housings forvarious injection purposes and it is easy to maintain constituentcomponents of the syringe is easy.

The holding portion and the driving portion to be regulated may beloaded into the housing while being temporarily fixed to each other byan adhesive tape or a paste, for example, before the two portions areloaded into the housing. Alternatively, the holding portion and thedriving portion may be loaded into the housing individually. Moreover,the loading position of the nozzle portion may also be regulated by theregulating means. Since a nozzle portion includes a passage throughwhich the injection objective substance is injected, the regulatingmeans may also regulate the loading position of the nozzle portion.

The driving portion may include an ignition charge or a gas generatingagent that combusts with a voltage, received from a power sourceportion, so as to generate a combustion gas. Furthermore, the drivingportion may also apply the injection energy to the injection objectivesubstance with pressure of the combustion gas. The regulating means mayregulate a loading position of the power source portion, the holdingportion, and the driving portion in relation to the housing so that thethree constituent portions are always loaded in the same order into thehousing. Since the relative loading position of the respectiveconstituent portions is regulated by the regulating means, it ispossible to efficiently realize various injection modes withoutimpairing the user's convenience.

In the above aspect, although the loading position of the power sourceportion is regulated by the regulating means, the loading position ofthe power source portion may not be regulated by the regulating means.That is, when the power source portion is included in the syringe, theregulating means may regulate a loading position of the holding portionand the driving portion in relation to the housing as described above.Furthermore, a loading position of the power source portion may not beregulated by the regulating means when the power source portion isloaded into the housing. A voltage required for combustion of theignition charge or the like may be applied to the driving portionmultiple times depending on a storage capacity of the power sourceportion. In such a case, since it is not necessary to detach the powersource portion from the housing whenever the injection objectivesubstance is injected, the loading position of the power source portionmay not be regulated by the regulating means. Moreover, depending on thestorage capacity, the power source portion can be removed from thehousing independently from the driving portion and the holding portion,thereby improving the convenience during replacement or the like.

The driving portion, the holding portion, and the nozzle portion may beformed so as to be superimposed in an axial direction of the housingwhen loaded into the housing. In this situation, the three constituentcomponents are sequentially loaded from one direction into the housingthrough an opening of the housing. In this case, the regulating meansincludes a first tapered surface which is a continuous outer peripheralsurface extending from the driving portion toward the holding portionwhen the three portions are superimposed on each other. A radius of thecontinuous outer peripheral surface increases as the outer peripheralsurface advances from the driving portion toward the holding portion.The regulating means also includes a second tapered surface which is acontinuous inner peripheral surface on the housing and corresponds tothe first tapered surface.

The first and second tapered surfaces form the regulating means. Thefirst tapered surface is formed when the driving portion, the holdingportion, and the nozzle portion are superimposed on each other. Thesecond tapered surface is provided on the housing to which theconstituent portions are loaded. These tapered surfaces are formed sothat the radii thereof increase as the tapered surfaces advance towardthe opening of the housing through which the constituent portions areloaded. Since the radii increase in the order of the driving portion,the holding portion, and the nozzle portion, if a user tries to load theholding and nozzle portions into the housing prior to the drivingportion, the nozzle portion will not advance in the housing beyond itsown loading position. As a result, it is not possible to load thedriving portion after the holding and nozzle portions are loaded. Thus,the user can recognize an error in the loading order of the constituentportions of the syringe.

Instead of using the tapered surfaces, the regulating means may includea first outer peripheral surface and a second inner peripheral surface.The first outer peripheral surface is a step-shaped outer peripheralsurface and includes an outer peripheral surface of the driving portionand an outer peripheral surface of the holding portion, having a largerradius than a radius of the outer peripheral surface of the drivingportion. The second inner peripheral surface is a step-shaped innerperipheral surface formed on the housing and corresponds to the firstouter peripheral surface. The step-shaped outer peripheral surface andinner peripheral surface have different radii, since the outerperipheral surface is not continuous to the driving portion and theholding portion, and the inner peripheral surface of the housingcorresponds thereto. Thus, it is possible to regulate the loadingposition of the driving portion and the holding portion. The drivingportion and the holding portion may be disposed on the same axis inrelation to the housing. Furthermore, the power source portion and thenozzle portion may be disposed on the same axis.

The syringe according to the present invention may employ anotherregulating means as long as it is configured such that, when a certainconstituent portion is incorrectly loaded into the housing and reachesits original loading position, the loading of the other constituentportions is inhibited, whereby users can recognize an error in theloading order.

The driving portion may have a driving-side opening through which theinjection energy is applied to the holding portion. The holding portionmay have an accommodation hole in which the injection objectivesubstance is accommodated. The accommodation hole may have anaccommodation hole-side end portion that receives the injection energyreceived through the driving-side opening. In this case, an annularprojection is formed on any one of the driving portion and the holdingportion. The annular projection surrounds the driving-side opening orthe accommodation hole-side end portion and deforms in the loading stateto seal a space between the driving-side opening and the accommodationhole-side end portion. Alternatively, an annular groove is formed on anyone of the driving portion and the holding portion. The annular groovesurrounds the driving-side opening or the accommodation hole-side endportion and engages with the annular projection in the loading state toseal a space between the driving-side opening and the accommodationhole-side end portion.

The injection energy applied through the driving-side opening istransmitted to the accommodation hole-side end portion of the holdingportion. The injection energy is subsequently applied to the injectionobjective substance accommodated in the accommodation hole. As describedabove, in the syringe according to the present invention, the drivingportion and the holding portion are configured to be independent fromeach other and are loaded into the housing. With this configuration, ifthe injection energy is not appropriately applied between the drivingportion and the holding portion, the injection objective substance isnot properly injected to the injection target area. Thus, the deformableannular projection is provided on the driving portion or the holdingportion. Furthermore, the annular projection and the annular groove,which are configured to engage with each other, are provided on thedriving portion and the holding portion, respectively. Thus, it ispossible to enhance the sealing of the space between the driving-sideopening and the accommodation hole-side end portion and to suppress theinjection transmitted from the driving portion from leaking outside.Moreover, it is possible to inject the injection objective substance tothe injection target area satisfactorily.

EFFECT OF THE INVENTION

It is possible to provide a syringe that can facilitate injection of aninjection liquid in various purposes, thereby enhancing the convenienceof a syringe user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a schematic configurationin an assembled state, of a syringe according to a first embodiment ofthe present invention.

FIG. 2 is a diagram illustrating the order of loading constituentportions of the syringe illustrated in FIG. 1 and a relativerelationship of the respective constituent portions.

FIG. 3 is a diagram for describing an embodiment in which the order ofloading a power source portion of the syringe illustrated in FIG. 1 isdifferent from the order of loading illustrated in FIG. 1.

FIG. 4 is a first diagram illustrating a detailed relative relationshipbetween a driving portion and a holding portion of the syringeillustrated in FIG. 1.

FIG. 5 is a second diagram illustrating a detailed relative relationshipbetween a driving portion and a holding portion of the syringeillustrated in FIG. 1.

FIG. 6 is a diagram illustrating the order of loading constituentportions of a syringe according to a second embodiment of the presentinvention and a relative relationship of the respective constituentportions.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a syringe 70 according to an embodiment of the presentinvention will be described with reference to the drawings. Although thesyringe 70 is a so-called needleless syringe having no injection needle,the present invention can be applied regardless of presence of aninjection needle. Moreover, the following embodiments are merelyexamples for description, and the present invention is not limited tothe disclosed embodiments.

First Embodiment

FIG. 1 is a cross-sectional view illustrating a schematic configurationof the syringe 70 in a state where assembling of the syringe 70 issubstantially completed. FIG. 2 is a diagram illustrating the order ofloading the constituent portions thereof to assemble the syringe 70. Asillustrated in FIG. 2, the syringe 70 has a housing 5 which serves as amain body thereof. The syringe 70 also includes a power source portion1, a driving portion 2, a holding portion 3, and a nozzle portion 4,which are sequentially loaded into the housing 5. Finally, theseconstituent portions 1-4 are fixed to the housing 5 by a fixing ring 6.In this way, the syringe 70 is assembled.

Specifically, the housing 5 has a hollow shape. A loading opening 52 isformed at one end in an axial direction thereof so that the constituentportions 1-4 can be loaded in the housing 5. On the other hand, anopening 53 is formed at the other end in the axial direction of thehousing 5. The opening 53 exposes, to the outside, an apex portion of apress button switch 11 (described later) provided in the power sourceportion 1 which is loaded first into the housing 5. Moreover, thehousing 5 has a hollow portion having an inner peripheral surface whichis formed as a continuous tapered surface 50. The tapered surface 50 isformed so that the radius (the inner diameter of the housing 5) thereofincreases as the tapered surface advances from the opening 53 to theloading opening 52 (that is, along the axis of the housing 5). In thesyringe 70 of the present embodiment, a side of the housing 5 close tothe opening 53 is referred to as an upstream side and the side close tothe loading opening 52 is referred to as a downstream side. This isbased on the flowing direction when an injection liquid 34 is injectedin a state where the respective constituent portions are loaded into thehousing 5 and assembling of the syringe 70 is completed.

The constituent portions 1-4 have individual functions and formedindependently. They are sequentially loaded into the housing 5 throughthe loading opening 52, and the loading state illustrated in FIG. 1 isformed. The power source portion 1 is a power supply for supplying powerto an igniter 22 provided in the driving portion 2 described later. Thepower source portion 1 generates a voltage between power source-sideelectrodes 12 using the power of a battery included therein when a userpresses the press button switch 11. The power source-side electrodes 12are formed as a pair of electrodes including first and second projectingelectrodes. The first projecting electrode is positioned on the centralaxis of the syringe 70 (the housing 5). The second projecting electrodeis separated by a predetermined distance from the first electrode.

The driving portion 2 has a gas generating agent 25 therein. Pressure ofa combustion gas is generated when the gas generating agent 25 combustsas injection energy for the injection liquid accommodated in the holdingportion 3 described later. The driving portion 2 applies the generatedpressure of combustion gas. Specifically, driving-side electrodes 21,corresponding to the power source-side electrodes 12 of the power sourceportion 1, are formed on an end surface of the driving portion 2. Thedriving-side electrodes 21 are formed as a pair of electrodes includingfirst and second small circular electrodes. The first small circularelectrode is positioned on the central axis of the syringe 70 (thehousing 5). The second small circular electrode has the same radius asthe predetermined distance, formed in a cylindrical form around thefirst small circular electrode. Since the driving-side electrodes 21 areformed in this manner, it is possible to maintain sufficient contactbetween the driving-side electrodes 21 and the power source-sideelectrodes 12. The sufficient contact can be maintained regardless of arelative position (the relative position in a rotation direction aboutthe central axis of the syringe 70) of the power source portion 1 inrelation to the driving portion 2.

The driving-side electrodes 21 are connected to the igniter 22 providedin the driving portion 2. The igniter 22 is a known electric ignitiondevice. When the power source portion 1 applies a voltage between thedriving-side electrodes 21, current flows and an ignition chargeprovided in the igniter 22 combusts. In this case, products generated bycombustion of the ignition charge flow toward the gas generating agent25 disposed in a combustion chamber 24 adjacent to the igniter 22. As aresult, combustion of the gas generating agent 25 in the combustionchamber 24 starts. When a large amount of combustion gas is generated bycombustion of the gas generating agent 25, pressure is applied to ametallic piston 23 provided adjacent to the combustion chamber 24. Thepiston 23 is propelled toward the downstream side of the syringe 70. InFIG. 1, an end portion of the combustion chamber 24 close to the holdingportion 3, which is blocked by the piston 23, is a driving-side opening.

Examples of the ignition charge used in the igniter 22 preferablyinclude a propellant (ZPP) containing zirconium and potassiumperchlorate, a propellant (THPP) containing titanium hydride andpotassium perchlorate, a propellant (TiPP) containing titanium andpotassium perchlorate, a propellant (APP) containing aluminum andpotassium perchlorate, a propellant (ABO) containing aluminum andbismuth oxide, a propellant (AMO) containing aluminum and molybdenumoxide, a propellant (ACO) containing aluminum and copper oxide, and apropellant (AFO) containing aluminum and iron oxide, or a propellantcomposed of a combination of a plurality of the propellants. Thesepropellants exhibit such characteristics that, although the propellantsgenerate hot and high-pressure plasma during combustion immediatelyafter ignition, when combustion products condense at a room temperature,the propellants do not contain gaseous components and the pressuregenerated decreases abruptly.

Moreover, examples of the gas generating agent 25 disposed in thecombustion chamber 24 preferably include a single base smokelesspropellant including 98% by mass of nitrocellulose, 0.8% by mass ofdiphenylamine, and 1.2% by mass of potassium sulfate. Moreover, variousgas generating agents used in a gas generator for airbags and a gasgenerator for seatbelt pretensioners may be used. A predetermined gasgenerated during combustion of the gas generating agent 25 containsgaseous components in a room temperature unlike the propellant. The gasgenerating agent 25 may not be used, and the igniter 22 and the piston23 may form the driving portion 2.

The holding portion 3 accommodates the injection liquid 34 which is aninjection objective substance injected by the syringe 70. Specifically,a through-hole (accommodation hole) 33 is formed at the center of theholding portion 3 so as to follow the central axis of the housing 5 in astate where the holding portion 3 is loaded into the housing 5 asillustrated in FIG. 1. Moreover, the injection liquid 34 is accommodatedin the space of the through-hole 33 between an upstream plug 31 and adownstream plug 32. The upstream plug 31 and the downstream plug 32 aremade from rubber, the surface of which is coated with a thin layer ofsilicon oil. As a result, the injection liquid does not leak whenaccommodating the injection liquid 34, and the injection liquid 34 canmove inside the through-hole 33 smoothly with sliding of the piston 23which will be described later. Moreover, an end portion of thethrough-hole (accommodation hole) 33 close to the driving portion 2,which is blocked by the upstream plug 31, is an accommodation hole-sideend portion.

The nozzle portion 4 has a passage for injecting the injection liquid 34accommodated in the holding portion 3 into an injection target(injection target area) outside the syringe 70. Specifically, a nozzle43 for injecting the injection liquid 34 is formed in the nozzle portion4. Furthermore, a recess 41 configured to accommodate the downstreamplug 32 is formed in a portion of the nozzle portion 4 facing thedownstream plug 32 in a state where the nozzle portion 4 is loaded intothe housing 5 as illustrated in FIG. 1. The recess 41 has substantiallythe same diameter as the downstream plug 32 and has a slightly largerdepth than the length of the downstream plug 32. With this structure,when pressure is applied to the injection liquid 34 due to injectionenergy from the driving portion 2, the downstream plug 32 can beaccommodated in the recess 41. When the downstream plug 32 isaccommodated in the recess 41, the pressurized injection liquid 34 isreleased from the space in the through-hole 33 of the holding portion 3.A passage 42 for guiding the released injection liquid 34 up to thenozzle 43 is formed so as to extend in a direction vertical to thecentral axis of the syringe 70. With this configuration, the releasedinjection liquid 34 is injected from the nozzle 43 into the injectiontarget through the passage 42. Moreover, since the recess 41 has such adepth that the downstream plug 32 is accommodated therein, it ispossible to prevent the injection of the injection liquid 34 from beinginhibited by the downstream plug 32.

A plurality of nozzles 43 or only one nozzle 43 may be formed in thenozzle portion 4. When a plurality of nozzles 43 are formed, passages 42corresponding to the respective nozzles 43 are formed so that thereleased injection liquid is delivered to the respective nozzles 43.Further, the respective nozzles 43 are preferably disposed at equalintervals around the central axis of the syringe 70. Moreover, thediameter of the nozzle 43 is set appropriately by taking injectionpressure applied to the injection liquid 34, properties (viscosity) ofthe injection liquid and the like into consideration.

As described above, in the syringe 70, the power source portion 1, thedriving portion 2, the holding portion 3, and the nozzle portion 4 areformed independently from each other. Furthermore, the respectiveconstituent portions 1-4 are sequentially loaded into the housing 5 asillustrated in FIG. 2, whereby the loading state illustrated in FIG. 1is created.

In this manner, when the constituent portions of the syringe 70 areconfigured to be independent from each other, users can selectconstituent portions according to the purpose of injection and combinethe constituent portions to assemble a final syringe 70. For example, aplurality of types of driving portions 2 having different kinds andamounts of gas generating agents 25 may be prepared. As a result, aninjection depth of the injection target can be adjusted while changing apressure profile applied to the injection liquid 34. Moreover, aplurality of types of holding portions 3 corresponding to differentkinds and amounts of injection liquid may be prepared. As a result, thekinds and amount of the injection liquid 34 injected to an injectiontarget can be adjusted according to the state or the like of theinjection target. For example, the dose of injection liquid can beadjusted according to the injection target in such a way that the doseof injection liquid injected to the skin structure of adults is to bedifferent from the dose of injection liquid injected to the skinstructure of kids. Further, a plurality of types of nozzle portions 4having different numbers of nozzles 43 and different nozzle diametersmay be prepared so that an injection mode of the injection liquid 34ideal for an injection target can be selected. A user selects onedriving portion 2, one holding portion 3, and one nozzle portion 4 inorder to attain an intended injection purpose. The user then loads therespective constituent portions into the housing 5 through the loadingopening 52 as illustrated in FIG. 2 to create a state where the syringe70 gets ready for use. In this way, it is possible to facilitateinjection of injection liquid ideal for various purposes.

The respective constituent portions are preferably configured such thata predetermined unified paint or design is applied to the external shapethereof. As a result, users can easily select one driving portion 2, oneholding portion 3, and one nozzle portion 4 to be loaded into thehousing to be prepared for injection. For example, the driving portions2 may be painted in blue, the holding portions 3 may be painted inyellow, and the nozzle portions 4 may be painted in red. In this way,users are prevented from selecting a plurality of driving portions 2 bymistake.

As illustrated in FIGS. 1 and 2, the power source portion 1 is loadedfirst into the housing 5. When the power source portion 1 is loaded intothe housing 5 with the surface of the press button switch 11 facing theinside of the housing 5, a stepped portion 13 collides with a steppedportion 54. Here, the stepped portion 13 is provided around the pressbutton switch 11 and the stepped portion 54 is provided around theopening 53 of the housing 5. With this configuration, a loading positionof the power source portion 1 is determined. At this loading position,an apex surface of the press button switch 11 is flush with the endsurface close to the opening 53, of the housing 5.

The syringe 70 is configured such that a voltage applied from the powersource portion 1 is applied to the driving portion 2 to combust the gasgenerating agent 25 to generate a combustion gas. Furthermore, theinjection liquid 34 is pressurized by the combustion gas, and thepressurized injection liquid 34 is injected outside from the nozzle 43.Thus, the constituent portions have to be loaded into the housing 5 inthe order of the power source portion 1, the driving portion 2, theholding portion 3, and the nozzle portion 4 as illustrated in FIG. 2. Ifthe constituent portions are not loaded in this order, it is notpossible to inject the injection liquid 34 using the syringe 70.

Thus, the syringe 70 adopts a configuration for defining the loadingposition of the respective constituent portions in the housing 5 so thatthe respective constituent portions are loaded into the housing 5 in anappropriate order. That is, a user can recognize a loading error whenthe respective constituent portions are not loaded in an appropriateorder. Specifically, the outer peripheral surfaces of the respectiveconstituent portions are formed as a tapered surface (first taperedsurface) so as to correspond to the tapered surface 50 (the secondtapered surface) which is the inner peripheral surface of the housing 5.As described above, the tapered surface 50 is formed so that the radius(outer diameter) of the tapered surface 50 increases as the taperedsurface advances from the upstream side to the downstream side. Theouter peripheral surfaces 10, 20, 30, and 40 of the respectiveconstituent portions are formed so as to correspond to the taperedsurface 50 in the order of loading the same into the housing 5. That is,the outer peripheral surfaces of the four constituent portions 1-4 forma continuous tapered surface (first tapered surface) so as to correspondto the tapered surface 50 close to the housing 5 in a state where therespective constituent portions are superimposed in the housing 5 in theaxial direction as illustrated in FIG. 1.

Since the outer peripheral surfaces 10, 20, 30, and 40 of the respectiveconstituent portions are formed so as to form a continuous taperedsurface when the outer peripheral surfaces are superimposed, the loadingpositions of the constituent portions in the housing 5 are uniquelydetermined as illustrated in FIG. 1 in order to create a state where thesyringe 70 can be used. If the holding portion 3 is loaded into thehousing 5 prior to the driving portion 2, the holding portion 3 cannotadvance toward the deeper side (the upstream side) than a position wherethe outer peripheral surface 30 makes contact with a portion of thecorresponding tapered surface 50. That is, a loading position is locatedwhere the holding portion 30 is to be loaded. With this structure, whenthe user tries to load the driving portion 2 subsequently, since a statewhere it is not possible to load the driving portion 2 is created, theuser can immediately recognize where an error occurs in the loadingorder. Thus, the tapered surface 50 (second tapered surface) of thehousing 5 and the continuous tapered surface (first tapered surface)correspond to the regulating means. Here, the continuous tapered surfaceis formed when the outer peripheral surfaces 10, 20, 30, and 40 of theconstituent portions 1-4 are superimposed on each other.

When the respective constituent portions are loaded into the housing 5as illustrated in FIG. 1, the fixing ring 6 is inserted into the housing5 so as to make contact with the end surface of the nozzle portion 4located closest to the downstream side. An external thread formed on theouter circumference of the fixing ring 6 engages with an internal thread51 formed near the end portion (the loading opening 52) of the innerperipheral surface of the housing 5. In this way, the constituentportions loaded into the housing 5 can be pressed and fixed with thenozzle portion 4 interposed.

Modified Example 1

In the embodiment, the power source portion 1 is also loaded into thehousing 5 through the loading opening 52 together with the otherconstituent portions. However, in place of such a configuration, thepower source portion 1 may be loaded into the housing 5 from theupstream side separately from the driving portion 2 and the like. Inthis case, a stepped portion 14 is provided around an end surface of thepower source portion 1 opposite the end surface where the press buttonswitch 11 is provided. Moreover, a recess 55 in which the power sourceportion 1 is accommodated is formed in a portion of the housing 5 closeto the opening 53. A projection 56 is provided in a space connecting therecess 55 and the space in the housing 5 defined by the tapered surface50. When the power source portion 1 is loaded in the recess 55, thestepped portion 14 close to the power source portion 1 collides with theprojection 56 close to the housing 5, whereby the loading position ofthe power source portion 1 is determined. The loaded power sourceportion 1 is fixed to the housing 5 by known fixing means. For example,the power source portion 1 can be detachable from the housing by asnap-fit of the power source portion 1. When the power source portion 1is loaded into the housing 5 in this manner, the power source-sideelectrodes 12 are exposed to the space in the housing 5 defined by thetapered surface 50. Furthermore, the power source-side electrodes 12 cancome into contact with the driving-side electrodes 21 of the drivingportion 2 loaded through the loading opening 52 as illustrated in FIG.1.

The power source portion 1 can supply an electric power to the drivingportion 2 several times depending on the storage capacity. In this case,as illustrated in FIG. 1, it may be inconvenient to load the powersource portion 1 into the housing 5 together with the other constituentportions such as the driving portion 2 whenever the injection liquid 34is injected. Thus, it is possible to diminish inconveniences associatedwith loading of the power source portion 1 when the power source portion1 is loaded separately from the other constituent portions asillustrated in FIG. 3. That is, the power source portion 1 does not havea tapered surface which is used for determining the loading position.After the power source portion 1 supplies electric power for apredetermined number of times corresponding to the storage capacity, thepower source portion 1 may be detached from the housing and a new powersource portion 1 may be loaded.

Modified Example 2

FIG. 4 illustrates a relative relationship between the driving portion 2and the holding portion 3 according to the present modification. The gasgenerating agent 25 is disposed in the combustion chamber 24, and thegas generating agent 25 combusts with ignition of the igniter 22 togenerate a combustion gas, whereby the piston 23 is pressed. In thiscase, the piston 23 moves from the opening (the driving-side opening) 24a close to the driving portion 3, of the combustion chamber 24 towardthe holding portion 3. On the other hand, on the holding portion 3 side,the piston 23 advances into the end portion (the accommodation hole-sideend portion) 33 a of the through-hole 33 in which the upstream plug 31,the injection liquid 34, and the downstream plug 32 are disposed. Thisway, the injection energy due to the combustion gas of the gasgenerating agent 25 is transmitted to the injection liquid 34 with theupstream plug 31 interposed therebetween.

Here, an annular projection 26 is formed on the end surface of thedriving portion 2, close to the holding portion 3, so as to surround theopening 24 a. The annular projection 26 is formed from relatively softmetal such as aluminum. When the respective constituent portions areloaded into the housing 5 and are fixed by the fixing ring 6 to generatepressing force as illustrated in FIG. 1, the projection 26 collapses anddeforms between the driving portion 2 and the holding portion 3 with thepressing force. With this deformation, the transmission of injectionenergy from the piston 23 to the upstream plug 31 is not inhibited. As aresult, since the deformed annular projection 26 surrounds and seals thespace between the driving portion 2 and the holding portion 3 around thethrough-hole 33 and the combustion chamber 24, it is possible tosuppress the combustion gas of the gas generating agent 25 from leakingoutside from the space between the driving portion 2 and the holdingportion 3. It is also possible to allow the injection energy to beeffectively transmitted to the injection liquid 34.

Modified Example 3

FIG. 5 illustrates a relative relationship between the driving portion 2and the holding portion 3 according to the present modification. FIG. 5illustrates a configuration in which an annular projection 27 and anannular groove 28 are formed instead of the annular projection 26illustrated in FIG. 4. The FIG. 5 configuration allows injection energyto be effectively transmitted to the injection liquid 34. Specifically,the annular projection 27 is formed on an end surface of the drivingportion 2, close to the holding portion 3, so as to surround the opening24 a. The annular projection 27 does not deform at the time of fixing tothe housing 5 unlike the annular projection 26. Instead, the annularprojection 27 engages with the annular groove 28 formed on an endsurface of the holding portion 3, close to the driving portion 2, so asto surround the end portion 33 a. The depth of the annular groove 28 isset to be slightly larger than the height of the annular projection 27.

As a result, when the annular projection 27 engages with the annulargroove 28, the projection 27 and the groove 28 surround and seal thespace between the driving portion 2 and the holding portion 3 around thethrough-hole 33 and the combustion chamber 24. Thus, it is possible tosuppress the combustion gas of the gas generating agent 25 from leakingoutside from the space between the driving portion 2 and the holdingportion 3 and to allow the injection energy to be effectivelytransmitted to the injection liquid 34.

Second Embodiment

A second embodiment of the syringe 70 will be described based on FIG. 6.In this embodiment, the regulating means determines the loading positionof the respective constituent portions loaded into the housing 5. Sincethe other constituent portions other than the regulating means, of thesyringe 70 according to the second embodiment are the same as those ofthe syringe 70 according to the first embodiment, these constituentportions are denoted by the same reference numerals, and descriptionthereof will be omitted.

In the present embodiment, the external shape of the power sourceportion 1, the driving portion 2, the holding portion 3, and the nozzleportion 4 loaded into the housing 5 are formed in an approximatelycylindrical shape. Furthermore, the radii (outer diameters) of the outerperipheral surface of the respective constituent portions are designedso as to increase in the order of the outer peripheral surfaces 100-400of the four constituent portions 1-4. Thus, in the present embodiment,when the respective constituent portions are superimposed so as to faceeach other in the housing 5, the outer peripheral surfaces of therespective constituent portions do not forma continuous tapered surfaceunlike the first embodiment but form a step-shaped discontinuous outerperipheral surface. The inner peripheral surface of the housing 5 isformed so as to correspond to the outer peripheral surfaces of therespective constituent portions. Specifically, four inner peripheralsurfaces 501-504 are formed so as to respectively correspond to theouter peripheral surfaces 100-400 of the four constituent portions 1-4.The radii (inner diameters) of the inner peripheral surfaces 501-504 areset so as to increase in that order. Thus, the inner peripheral surfaceof the housing 5 is also formed as a step-shaped discontinuous surface.

Since the outer peripheral surfaces 100-400 form a step-shapeddiscontinuous outer peripheral surface when the constituent portions aresuperimposed and the inner peripheral surface of the housing 5corresponds to the outer peripheral surface, the loading positions ofthe constituent portions are uniquely determined as illustrated inFIG. 1. With this configuration, users can recognize an error in theloading order immediately. Thus, the step-shaped discontinuous innerperipheral surfaces 501-504 and the step-shaped discontinuous outerperipheral surface correspond to a regulating means according to thepresent invention.

Moreover, the external shape of the respective constituent portions mayhave a circular truncated external shape so that the outer peripheralsurface has a tapered surface instead of the cylindrical shape.

According to the syringe 70 of the present invention, for example,cultured cells, stem cells, and the like may be seeded or inoculatedinto injection target cells or scaffold tissues (scaffolds) in the fieldof the regenerative medicine of human, in addition to the case where theinjection liquid is injected into the skin structure. For example, asdescribed in Japanese Patent Application Publication No. 2008-206477,the syringe 70 may inject cells which may be appropriately determined bythose skilled in the art depending on a transplantation portion and thepurpose of the cell regeneration. For example, these cells includeendothelial cells, endothelial precursor cells, myeloid cells,preosteoblast, chondrocytes, fibroblast, skin cells, muscle cells, livercells, kidney cells, intestinal tract cells, and stem cells, as well asall cells considered in the field of the regenerative medicine. Morespecifically, a liquid (cell suspension) containing the cells to beseeded or inoculated is accommodated in the holding portion 3, and theliquid pressurized with combustion of the gas generating agent 25. Inthis way, predetermined cells are injected and transplanted to thetransplantation portion.

Further, the syringe 70 according to the present invention may be alsoused for delivering DNA or the like to cells or scaffold tissues(scaffolds) as described in Japanese Patent Application Publication No.2007-525192. In this case, it is possible to suppress an adverse effecton cells themselves or scaffold tissues (scaffolds) themselves when thesyringe 70 according to the present invention is used, as compared withwhen the delivery is performed using a needle. Therefore, it can be saidthat the use of the syringe 70 according to the present invention ismore desirable.

Further, the syringe 70 according to the present invention is ideallyuseful, for example, when various genes, cancer inhibiting cells, lipidenvelops, and the like are directly delivered to target tissues and whenantigen genes are administered to enhance the immunity againstpathogens. In addition to the above, the syringe 70 can be also used,for example, in the field of medical treatment for various diseases (forexample, see Japanese Translation of PCT Application No. 2008-508881 andJapanese Translation of PCT Application No. 2010-503616) and the fieldof immunological medical treatment (for example, see JapaneseTranslation of PCT Application No. 2005-523679). The field, in which thesyringe 70 is usable, is not intentionally limited.

EXPLANATION OF REFERENCE NUMERALS

-   -   1: Power source portion    -   2: Driving portion    -   3: Holding portion    -   4: Nozzle portion    -   5: Housing    -   6: Fixing ring    -   10, 20, 30, 40: Outer peripheral surface    -   12: Power-side electrode    -   21: Driving-side electrode    -   22: Igniter    -   23: Piston    -   24: Combustion chamber    -   24 a: Opening    -   25: Gas generating agent    -   26: Annular projection    -   31: Upstream plug    -   32: Downstream plug    -   33: Through-hole    -   33 a: End portion    -   34: Injection liquid    -   41: Recess    -   43: Nozzle    -   70: Syringe    -   100, 200, 300, 400: Outer peripheral surface    -   501, 502, 503, 504: Inner peripheral surface

1. A syringe that injects an injection objective substance into aninjection target area of a living body, the syringe comprising: ahousing; a holding portion that accommodates the injection objectivesubstance; a driving portion that applies injection energy toward theinjection objective substance accommodated in the holding portion, fromthe holding portion, wherein the driving portion includes an ignitioncharge or a gas generating agent that combusts with a voltage appliedfrom a power source portion and applies the injection energy to theinjection objective substance with pressure of a combustion gas that isgenerated by combustion of the ignition charge or the gas generatingagent; a nozzle portion that includes a passage, through which theinjection objective substance injected from the holding portion flows,and injects the injection objective substance from an open end of thepassage to the injection target area, wherein the holding portion, thedriving portion, and the nozzle portion are loaded into the housingindependently, whereby a state where the injection objective substancecan be injected is established; and regulating means for regulating aloading position of the holding portion and the driving portion withinthe housing so that a loading state where the holding portion and thedriving portion are always loaded in the same order into the housing isestablished for injection of the injection objective substance, whereina loading position of the power source portion is not regulated by theregulating means when loading into the housing is implemented.
 2. Thesyringe according to claim 1, wherein: the driving portion, the holdingportion, and the nozzle portion are formed so as to be superimposed inan axial direction of the housing when loaded into the housing, and thedriving portion, the holding portion, and the nozzle portion aresequentially loaded from one direction into the housing through anopening of the housing, and the regulating means comprises: a firsttapered surface which is a continuous outer peripheral surface formed soas to extend from the driving portion toward the holding portion whenthe driving portion, the holding portion, and the nozzle portion aresuperimposed on each other, and which is formed so that a radius of thecontinuous outer peripheral surface gradually increases from the drivingportion toward the holding portion; and a second tapered surface whichis a continuous inner peripheral surface on a side of the housing andcorresponds to the first tapered surface.
 3. The syringe according toclaim 1, wherein: the driving portion, the holding portion, and thenozzle portion are formed so as to be superimposed in an axial directionof the housing when loaded into the housing, and the driving portion,the holding portion, and the nozzle portion are sequentially loaded fromone direction into the housing through an opening of the housing, andthe regulating means comprises: a first outer peripheral surface whichis a step-shaped outer peripheral surface and includes an outerperipheral surface of the driving portion and an outer peripheralsurface of the holding portion, which has a larger radius than a radiusof the outer peripheral surface of the driving portion; and a secondinner peripheral surface which is a step-shaped inner peripheral surfaceformed on the housing and corresponds to the first outer peripheralsurface.
 4. The syringe according to claim 1, wherein: the drivingportion has a driving-side opening which is an opening for applying theinjection energy to the holding portion, the holding portion has anaccommodation hole in which the injection objective substance isaccommodated and the accommodation hole has an accommodation hole-sideend portion that receives the injection energy applied from thedriving-side opening, and an annular projection, which surrounds thedriving-side opening or the accommodation hole-side end portion anddeforms in the loading state to seal a space between the driving-sideopening and the accommodation hole-side end portion, is formed on one ofthe driving portion and the holding portion.
 5. The syringe according toclaim 1, wherein: the driving portion has a driving-side opening whichis an opening for applying the injection energy to the holding portion,the holding portion has an accommodation hole in which the injectionobjective substance is accommodated and the accommodation hole has anaccommodation hole-side end portion that receives the injection energyapplied from the driving-side opening, an annular projection whichsurrounds the driving-side opening or the accommodation hole-side endportion is formed on one of the driving portion and the holding portion,and an annular groove, which surrounds the driving-side opening or theaccommodation hole-side end portion and engages with the annularprojection in the loading state to seal a space between the driving-sideopening and the accommodation hole-side end portion, is formed on theother one of the driving portion and the holding portion.
 6. A syringethat injects an injection objective substance into an injection targetarea of a living body, the syringe comprising: a housing; a holdingportion that accommodates the injection objective substance; a drivingportion that applies injection energy toward the injection objectivesubstance accommodated in the holding portion, from the holding portion,wherein the driving portion includes an ignition charge or a gasgenerating agent that combusts with a voltage applied from a powersource portion and applies the injection energy to the injectionobjective substance with pressure of a combustion gas that is generatedby combustion of the ignition charge or the gas generating agent; anozzle portion that includes a passage, through which the injectionobjective substance injected from the holding portion flows, and injectsthe injection objective substance from an open end of the passage to theinjection target area, wherein the holding portion, the driving portion,and the nozzle portion are loaded into the housing independently,whereby a state where the injection objective substance can be injectedis established; and a regulator configured to regulate a loadingposition of the holding portion and the driving portion within thehousing so that a loading state where the holding portion and thedriving portion are always loaded in the same order into the housing isestablished for injection of the injection objective substance, whereina loading position of the power source portion is not regulated by theregulating means when loading into the housing is implemented.